The present invention relates to railway tank cars, and in particular, to manifolded tank cars which may be interconnected to accommodate loading or unloading of the entire group of interconnected cars without movement thereof from a single point therealong, thereby accommodating consecutive loading, transporting and unloading of fluid ladings and facilitating the formation of unit trains.
The concept of providing fluid communication among a series of interconnected railway tank cars is disclosed in the prior art, but previous systems have failed to provide an inner tank connection arrangement which insured safe handling of the fluid ladings during transportation, and which also was convenient for loading and unloading of the fluid ladings from either end of the train.
For example, U.S. Pat. No. 1,542,116, issued to R. Welcker, discloses railway tank cars for interconnection in a manifolded arrangement from a single location, without moving or disconnecting the cars. However, Welcker's arrangement does not provide for continuous loading of the interconnected tanks from a single location, much less providing for continuous loading or unloading from either end of the tank car train. Furthermore, the inner tank lading connections disclosed by the Welcker patent are along the longitudinal axis of the tanks which is found to be a disadvantageous arrangement. In addition, the exposed valves in the Welcker patent must be individually and manually operated and are also a potential dangerous hazard.
United States Pat. No. 3,722,556, issued to William Jeffers et al, discloses a manifolded tank car arrangement which accommodates both loading and unloading of a string of interconnected tank cars from a single point, but Jeffers et al. provide the inner tank lading connections at the bottoms of the tank and also, in addition, they provide exposed and unprotected lading flow control valves. Furthermore, Jeffers et al. do not provide a symmetrical tank car which may be loaded or unloaded from either end thereof and which during loading automatically determines the final outage of the lading in the tank, a feature which is critically necessary with certain bulk lading commodities to accommodate product expansion in transit.